Looking for an old story

[Bmoviecollector]

The story I am looking for was about a (young saleswoman or insurance agent), do not remember exactly, that goes to a large house and/or castle for an appointment.  She meets with an eccentric man, possibly a doctor.  She is drugged and taken to a basement and or dungeon.  The eccentric man has a quirky assistant.  The young woman is put through several bondage experiences and is very frightened.  The story is almost light hearted and somewhat humorous.  The woman is let go and, if I remember correctly, does not remember the experience.  Any ideas are most appreciated.  Thank you in advance.